Split 6.5″ dia. Backer Plates for retrofitting Direct Tank Fill Flanges into existing water tanks 500041 Part No. 500041 Use two of these split backer casting when installing 500145, 500146 and 500147 Direct Tank Fill Flanges into existing water tanks. Quantity 2 required of this part. Gasket 500139 available. Part Number 500153 Full Backer Plates also available. Description Split 6.5" dia. Backer Plates for use with all Direct Tank Fill Flanges. Use Qty 2 of these when retrofitting 500145, 500146 or 500147 Direct Tank Fill Valve Flanges into existing water tanks. Download Part Drawing Weight (approx.) 1.1 lbs.